The specifications of electrical products for consumers change with each passing day, and trend for reducing sizes of mobile phones hasn't become slow. Therefore, the specifications of critical elements of optical lens also must been upgraded continuously to conform to consumers' demands. One of the most important characteristics of an optical lens may be its imaging quality and size. However, manufacturing an optical lens with perfect imaging quality and smaller size only may not depend only reducing the length of the optical lens. The process for manufacturing an optical lens must also consider the optical lens's material and assembly yield.
In conclusion, designing a small sized optical lens is more difficult than designing a traditional optical lens. Therefore, manufacturing an optical lens conformed to consumers' demands and upgrading its imaging quality are always hot targets with regard to industries, governments, and academia for a long time.